182 Botany. 



H. vulgare, L (SATIVUM, Pers.) is the cultivated Barley. 

 Variety generally cultivated is DISTICHUM, the two-rowed 

 form, but 4-6-rowed barleys are also grown. 



var. hexastichon (six-rowed form). 



1. Wheat field between Down and Keston, '04. This 

 form is interesting, because it was cultivated in the 

 Stone Age ; it frequently occurs as a casual amongst 

 corn crops on the chalk. W.H.G. 



NOTE. The cultivated cereals, some of which have been men- 

 tioned, belong to this Order ; others are : Triticum vulgare (Wheat), 

 Secale cereale (Rye, commonly grown as a green crop in this country), 

 Zea mais (Maize, Indian Corn, or Mealies), and Oryza sativa (Rice) ; 

 Bamboos are woody sometimes arborescent grasses. Wheat is 

 generally self- fertilised, and in some species of Barley the flowers 

 never open. The Sugar-cane (Saccharum officinarum) is tropical. 



ALLIANCE VIII. HELOBIE^. 



N.O. 1. HYDROCHARITACE&. Aquatics. 



1424. ELODEA canadensis, Mich. (ANACHARIS ALSINASTRUM, Bab.). 



Aquatic free-swimming P. The AMERICAN WATER- WEED 

 introduced into Ireland c. 1836, and into England c. 1841, 

 when it rapidly spread over all the inland waters, ousting 

 the native aquatics. The /. plant is found in Edinburgh ; 

 elsewhere in this country only the m. plant is known. 

 Flowering specimens are seen in the Woking Canal, Surrey, 

 but not often in Kent. 



1425. HYDROCHARIS morsus-ranae, L. (FROG-BIT), 78, P. A 



free-floating rootless aquatic ; common. Dioecious flowers 

 with half -concealed honey. 



1. This plant, Sagittaria sagittifolia and Butomus um- 

 bellatus were plentiful and wont to flower freely up 

 to '02 in the Marsh ditches between Dartford and 

 Greenhithe, but owing to the numerous factories 

 these aquatics are fast panning out. W.H.G. 



VALLISNERIA SPIRALIS, L., an aquatic alien, has been 

 introduced at A very Hill. 



1426. STRATIOTES aloides, L. (WATER SOLDIER), 7, P. An 

 , aquatic alien or denizen, very rare and probably always 



introduced (A very Hill). Dioecious fls. with half -concealed 

 honey. 



